Electrical locking device combined with an interphone system



Jan. 20, 1970 KAZUO SUGIYAMA' 3,491,353

ELECTRICAL LOCKING DEVICE COMBINED WITH AN INTERPHONE SYSTEM Filed Dec. 19, 1966 INVENTOR KAzuo SUGWAMA BY v ammawm j ATTORNEYS United States Patent 3,491,353 ELECTRICAL LOCKING DEVICE COMBINED WITH AN INTERPHONE SYSTEM Kazuo Sugiyama, Tokyo, Japan, assignor to Heiwa Denki Kabushiki Kaisha, Komukai-Nishimachi, Kawasaki-shi,

Japan Filed Dec. 19, 1966, Ser. No. 602,816 Claims priority, application Japan, Dec. 22, 1965,

40/104,159 Int. Cl. G081); H04m 1/00 US. Cl. 340286 4 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to an electrical locking device, particularly to an electrical locking device combined with an interphone system wired between an entrance door and a room.

The object of this invention is to provide an electrical locking device utilizing the lines of an interphone (doorphone) system comprising a follower unit positioned at an entrance door and a master unit positioned in a room, for remotely controlling the locking device by an unlocking switch arranged in the master unit and an unlocking circuit in the circuit of the follower unit.

The present invention will be explained in detail with a preferred embodiment illustrated in the accompanying drawings.

The figure shows a circuit diagram of an electrical locking device combined with an interphone system, embodying the present invention.

As shown in the drawing, a bridge circuit is composed of a circuit comprising a terminal A, a power source cell 10, a line 21, a balancing resistance 16, an electromagnet coil 18, a line 20, and a terminal B, and another circuit comprising the terminal B, another balancing resistance 12, another power source cell 11, and the terminal A The voltage of the cell is made equal to that of the cell 11, and the balancing resistance 12, another balancing resistance 16, and the series resistance value of the electromagnet coil 18 are equal with each other. Between the terminals A and B, there is provided with a chime mechanism oscillation circuit 8 and a blocking oscillation circuit 9. A series voltage of cells 10 and 11 in the reversed polarity is applied to contacts 13b and 13!) arranged opposite to an unlocking switch 13, and 13' respectively leading to terminals C and D of the lines 20 and 21. The pickup circuit of the chime mechanism is connected to a waiting switch 7, a talk switch 6, an amplifier 5 and into a speaker (or microphone) 4. The talk switch 6 and the waiting switch 7 form a gang. Between terminals E and F of the lines 20 and 21, there is parallelly provided with a calling switch 14 for the follower unit 2 and a speaker 15. Parallelly with this follower unit 2 and between terminals G and H, there is provided with the electromagnet 18 of the electrical locking device 3, the balancing resistance 16, a door switch 19, these parts being series connected with one another. Further a rectifier 17 is arranged in parallel with the balancing resistance 16.

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Now, the operation of the device of this invention will be explained in detail. Since the voltage of the cell 10 is equal to that of the cell 11, and the balancing resistances 12 and 16 and the series resistance value of the electromagnet coil 18 are equal with each other, the balance of the bridge circuit is maintained. Under this condition, no potential difference would develop across the terminals A and B, and so the device is in the state of waiting.

If the calling switch 14 of the follower unit 2 is pushed, the balancing resistance 16 and the electromagnet coil are short-circuited, breaking the balance of the bridge. Then a certain potential develops across the terminals A and B, the terminal A being negative and the terminal B positive. Then the current flows to the coil of the chime mechanism 8 through the diode. The oscillation of the chime mechanism is picked out and transmitted through the waiting switch 7 at the side 7a and the talk switch 6 at the side 6a and amplified by the amplifier 5 for sulficiently actuating the speaker 4.

After hearing the call signal from the speaker 5, a person in the room turns the talk switch 6 of the master unit 1 to the side 6b. By this operation the ganging waiting switch 7 also turns to the side 712. Under this condition the speaker 4 functions as a microphone. The sound from the microphone is amplified and transmitted through lines 20 and 21 to actuate the speaker 15 of the follower unit 2. If the talk switch 6 is re-set to the original position, the waiting switch also returns. Under this condition, the speaker 15 of the follower unit 2 acts as a microphone and actuates the speaker 4 of the master unit 1.

After the communication between two units thus have been ended, the talk switch 6 and the waiting switch 7 are turned to the sides 6a and 7a respectively for waiting the next call from the follower unit 2.

For unlocking the door, the unlocking switches 13, 13' are turned to the sides 13b and 13b. Since series voltage of cells 10 and 11 in a reversed polarity are directiy applied to the terminals, a large current fiows through lines to the rectifier 17 of the electrical locking device 3 for actuating the electromagnet 18. The manner for unlocking of a lock by the electromagnet 18 is not different from already-known electric locks in which a stopping arm 23 for a bolt 22 of the door is retracted from its stopping position by the action of the electromagnet 18. After this unlocking, the door can be opened by hand.

During this manual opening of the door, the door switch 19 is made open. This condition again breaks the balance of the bridge circuit and a potential develops across the terminals A and B, the terminal A being positive and the terminal B negative, just reversely in the above-mentioned case. By this potential the blocking oscillation circuit 9 is actuated, and the oscillation signals are amplified for sufiiciently actuating the speaker 4. By the oscillation sound from the speaker, the person can affirm the fact that the door opens. By the Way, if the lines 20 and 21 are cut, a similar oscillation sound will be heard from the speaker as an alarm signal.

After the unlocking switch has been returned, the stopping arm 23 again stops the bolt 22 in accordance with the shutting of the door for again establishing locking condition.

However, such re-locking may be made electrically by a suitable locking switch (not shown) provided on the follower unit 1, separately of the above-mentioned automatic locking.

As specifically mentioned in the above, the device of the present invention is a combination of an electrical locking device and an interphone system. By this device, the unlocking of the door can be made electrically according to the result of the conversation through the interphone, thereby eliminating the trouble to go to the entrance 'door and contributing to the prevention of crimes.

What I claim is: 1. An electrical locking system included in an interphone system which comprises a master unit positioned at a location inside a room,

a remote unit positioned at a location outside the room,

a lock control unit associated with a door between the room and the outside controllable to actuate a lock for the door,

an electrically connected balancing bridge circiut exist ing between the master unit and the lock control unit,

switch means associated with the remote unit to unbalance the bridge circuit when actuated,

signal means associated with the master unit actuated by the unbalancing of the bridge circuit,

means associated With the master unit operable to unbalance the bridge circiut and effect an unlocking of the lock controlled by the lock control circuit, and

switch means operable by the door to unbalance the balanced bridge circuit upon the opening of the door to signal the opening and closing of the door at the master unit.

2. An electrical locking system according to claim 1 4 which includes separate speakers at the master unit and at the remote unit, means to amplify signals received by the speakers, and Where each speaker acts as a microphone when receiving voice signals directed thereinto.

3. An electrical locking system according to claim 1 where the signal means associated with the master unit is an audible tone device which is actuated by the unbalancing of the bridge circuit.

4. An electrical locking system according to claim 1 which includes battery means in the bridge circuit connected in series to each other in opposite polarity, and both being of equal voltage.

References Cited UNITED STATES PATENTS 2,263,157 11/1941 Auth 340-286 X 3,284,571 11/1966 Wittig 179-l.4 X

JOHN W. CALDWELL, Primary Examiner C. M. MARMELSTEIN, Assistant Examiner US. Cl. X.R. l79---1-.4 

